Burgers are serious business, and like anything, it appears they can be trademarked. The West Coast-based burger chain In-N-Out filed a lawsuit against Smashburger on Monday over its alleged trademark infringement of one of the company’s burgers. In In-N-Out’s view, Smashburger’s “Triple Double” burger — launched earlier this summer — cuts way too closely to its own “Double-Double” burger.

Both Smashburger’s Triple Double and In-N-Out’s Double-Double are cheeseburgers that feature two burger patties and multiple slices of cheese sandwiched between toasted buns.

“Smashburger’s use of the Triple Double and Smashburger Triple Double marks is likely to confuse and mislead the consuming public, and injure In-N-Out, by causing consumers to believe incorrectly that Smashburger’s products originate from or are authorized by In-N-Out,” the lawsuit, first reported by the Orange County Register, states.

The Double Double is very much known far and wide as In-N-Out’s standard burger, the rock upon which its other patty sandwiches build their flavor profiles. Moreover, it’s a commonly understood tenet of trademark law that you have to “vigorously defend” your trademark, lest you eventually lose it. It’s why those words come up most times trademark litigation does, and the text of In-N-Out’s lawsuit doesn’t disappoint, detailing the many In-N-Out trademarks registered with the United States Patent and Trademark Office, and pointing out that it has used the relevant registered trademarks like the Double-Double burger since 1963 and the Triple Triple burger since 1966.

This isn’t even In-N-Out’s first branding- and trademark-related rodeo this year. The burger chain is known for its litigiousness when it comes to trademark and copyright, and actually sued a dry cleaning service called In-N-Out Cleaners based in Wichita, Kansas earlier this year. The company also sued a Utah restaurant called Chadder’s in 2007 and the delivery service DoorDash in 2015.

In the lawsuit, In-N-Out seeks monetary compensation as well as an injunction to cease the production and sale of Smashburger’s allegedly infringing burgers.